CN103643265A - Electroplating liquid for electrically depositing Cu-W-Co alloy coating and method thereof - Google Patents

Abstract

The invention relates to an electroplating solution for electrodepositing a Cu-W-Co alloy coating and a method thereof, belonging to the technical field of multi-element copper alloy electroplating technology. The electroplating solution includes components of the following concentrations: soluble copper salt, soluble cobalt salt, sodium tungstate, complexing agent, buffering agent, brightener, wetting agent, additive; the method for electrodepositing Cu-W-Co alloy coating It is: the above mixed reagent is used as the electroplating solution, the anode is graphite, and the cathode is treated high-conductivity pure copper or copper alloy substrate, at a pH of 4-11, a temperature of 25-80°C, and a current density of 1-20A/ Electroplating under the condition of dm ² for 0.5~3h can prepare Cu-W-Co alloy coating on the cathode. The electroplating solution is non-toxic, environment-friendly, stable and free of precious metals; the method has short technological process, low cost, low energy consumption, high benefit and convenient operation at low temperature.

Description

Electroplating solution and method for electrodepositing Cu-W-Co alloy coating

technical field

The invention relates to an electroplating solution for electrodepositing a Cu-W-Co alloy coating and a method thereof, belonging to the technical field of multi-element copper alloy electroplating technology.

Background technique

For a long time, the "universal contact" AgCdO has been widely used in various medium and low voltage due to its advantages of arc resistance, welding resistance, mechanical wear resistance, corrosion resistance, stable and low contact resistance, good processability and weldability. electrical appliances. Generally, the "universal contact" AgCdO is prepared by electroplating. Electroplating has the characteristics of low temperature operation, low cost, easy control of the process, and uniform composition. The prepared silver-containing electrical contact functional coating material also has good application effects in production practice. However, the plating solution often contains toxic cyanide, and silver resources are scarce and expensive. At the same time, due to "cadmium toxicity", the European Union's WEEE and ROHS directives have clearly banned the use of cadmium, lead and other six harmful substances in electronic and electrical products, and the silver recovery rate after contact failure is low, resulting in scarce and expensive resources.

In view of this, with the promotion of the concept of saving and environmental protection, the research on cadmium-free and silver-free copper-based electrical contact materials has been extensively researched and developed. Among them, copper-tungsten pseudoalloy is one of the hot spots in the research of copper-based electrical contact materials. Due to the large difference in the melting points of Cu and W components, the current preparation process is mainly based on powder metallurgy and its derivative processes.

Since it is impossible to directly electroplate Cu-W pseudoalloy from aqueous solution, it has been reported to add W particles to Cu plating solution to prepare Cu-W alloy by electrodeposition, but its hardness and oxidation resistance are still slightly insufficient. However, Co can improve the quality of powder metallurgy electrical contact materials and achieve the matching of mechanical properties and electrical properties. Since the Co-W alloy has the advantages of hardness, corrosion resistance, wear resistance, high temperature oxidation resistance, etc., the preparation of the Cu-W-Co multi-element alloy electrical contact coating process becomes the key, but because the Cu-Co alloy phase at room temperature Poor solubility, it is difficult to prepare Cu-W-Co multi-element alloys by conventional methods, but through thermodynamic analysis, it is possible to electroplate Cu-W-Co multi-element alloys in water solution, so the present invention adopts electroplating method to prepare Cu-W-Co Multiple alloys.

Contents of the invention

Aiming at the problems and deficiencies in the above-mentioned prior art, the present invention provides an electroplating solution for electrodepositing a Cu-W-Co alloy coating and a method thereof. The electroplating solution is non-toxic, environmentally friendly, stable, and free of precious metals; the method has short process flow, low cost, low energy consumption, high benefit, convenient low temperature operation, and under the condition of easy control, it can obtain high surface hardness, durable The Cu-W-Co alloy coating with strong corrosion resistance, wear resistance, electrical conductivity and high temperature oxidation resistance is realized by the following technical solutions.

An electroplating solution for electrodepositing a Cu-W-Co alloy coating, the electroplating solution includes components at the following concentrations: 5-50 g/L of soluble copper salt, 60-120 g/L of soluble cobalt salt, and 50-150 g/L of sodium tungstate L. Complexing agent 100~300g/L, buffering agent 5~40g/L, brightener 0.2~3g/L, wetting agent 0.1~1g/L, additive 0.1~1g/L, in which complexing agent and metal ion The mole fraction ratio is 1~1.3:1.

A method for electrodepositing a Cu-W-Co alloy coating, its concrete steps are as follows: to include the components of the following concentrations: soluble copper salt 5~50g/L, soluble cobalt salt 60~120g/L, sodium tungstate 50~ 150g/L, complexing agent 100~300g/L, buffering agent 5~40g/L, brightener 0.2~3g/L, wetting agent 0.1~1g/L, additive 0.1~1g/L mixed reagent is electroplating solution , in which the molar ratio of complexing agent to metal ion is 1~1.3:1, the anode is graphite, and the cathode is treated high-conductivity pure copper or copper alloy substrate, at a pH of 4~11 and a temperature of 25~80 ℃, current density of 1-20A/dm ² electroplating for 0.5-3h, that is, the Cu-W-Co alloy coating can be prepared on the cathode.

The soluble copper salt is copper sulfate, or a mixture of copper sulfate and copper chloride in any proportion.

The soluble cobalt salt is cobalt sulfate, or a mixture of cobalt sulfate and cobalt chloride in any proportion.

The complexing agent is pyrophosphate, pyrophosphoric acid, citrate, citric acid, potassium sodium tartrate, ethylenediamine, fluoboric acid, fluoborate or a mixture of several in any proportion.

The buffering agent is boric acid, borate, ammonium salt or acetate.

The brightener is one or more mixtures in any proportion of butynediol, polyethylene glycol, gelatin, saccharin, sodium saccharin, glucose, coumarin and thiourea.

The wetting agent is lauryl sulfate or dodecyl sulfonate.

The additive is rare earth chloride or rare earth sulfate.

The treatment process of the above-mentioned highly conductive pure copper or copper alloy substrate is: grinding-degreasing-water washing-pickling-water washing.

The stirring rate in the above electroplating process is 300~1000r/min.

The beneficial effects of the present invention are: (1) the electroplating solution is non-toxic, environmentally friendly, stable, and free of precious metals; (2) the method has short process flow, low cost, low energy consumption, high benefit, convenient low temperature operation, and is easy to use Under controlled conditions, a Cu-W-Co alloy coating with high surface hardness, corrosion resistance, wear resistance, strong electrical conductivity and high temperature oxidation resistance can be obtained.

Description of drawings

Fig. 1 is the Cu-W-Co alloy coating SEM figure in the embodiment of the present invention 1;

Fig. 2 is the Cu-W-Co alloy coating energy spectrogram in the embodiment of the present invention 1;

Fig. 3 is the Cu-W-Co alloy coating SEM figure in the embodiment of the present invention 2;

Fig. 4 is the energy spectrogram of Cu-W-Co alloy coating in the embodiment of the present invention 2;

Fig. 5 is the Cu-W-Co alloy coating SEM figure in the embodiment of the present invention 3;

Fig. 6 is an energy spectrum diagram of the Cu-W-Co alloy coating in Example 3 of the present invention.

Detailed ways

The present invention will be further described below in combination with the accompanying drawings and specific embodiments.

Example 1

The electroplating solution of the electrodeposited Cu-W-Co alloy coating, the electroplating solution comprises the components of the following concentrations: soluble copper salt 30g/L, soluble cobalt salt 90g/L, sodium tungstate 70g/L, complexing agent 205g/L L, buffering agent 15g/L, brightener 1.0g/L, wetting agent 0.1g/L, additive 0.1g/L, in which the molar ratio of complexing agent to metal ion is 1:1, and the soluble copper salt is sulfuric acid Copper, soluble cobalt salt is cobalt sulfate, complexing agent is sodium citrate, buffering agent is sodium borate, brightener is 1,4 butynediol, wetting agent is sodium lauryl sulfate, additive is cerium sulfate.

The method for electrodepositing a Cu-W-Co alloy coating, its specific steps are as follows: use the above-mentioned mixed reagent as the electroplating solution, the anode is graphite, and the cathode is treated red copper, at a pH of 6.5, a temperature of 55°C, and a current density of Electroplating for 2h under the condition of 3A/dm ² can prepare Cu-W-Co alloy coating on the cathode, as shown in Figures 1 and 2.

The composition mass percentage of the Cu-W-Co alloy coating prepared on the cathode is as follows: Cu61.12%, Co25.08%, W13.80%, and the surface hardness is 236HV. At room temperature, the coating has no corrosion in 3.5% NaCl solution. The contact resistance of the coating is 30.4mΩ, and the oxidation rate at 600°C is 4.63×10 ^-4 g/cm ² . The wear rate of the coating is 0.237mg/h when the coating is on the MMU-5G wear test machine, the load is 60N, the sliding speed is 50r/min, and the wear time is 0.5 hours.

Example 2

The electroplating solution of the electrodeposited Cu-W-Co alloy coating, the electroplating solution includes the following concentrations of components: soluble copper salt 35g/L, soluble cobalt salt 90g/L, sodium tungstate 70g/L, complexing agent 217.5g /L, buffering agent 15g/L, brightener 1.0g/L, wetting agent 0.1g/L, additive 0.1g/L, wherein the molar fraction ratio of complexing agent to metal ion is 1.3:1, and the soluble copper salt is Copper sulfate, soluble cobalt salt is cobalt sulfate, complexing agent is sodium citrate, buffering agent is boric acid, brightener is 1,4 butynediol, wetting agent is sodium lauryl sulfate, additive is cerium sulfate.

The method for electrodepositing a Cu-W-Co alloy coating, its specific steps are as follows: use the above-mentioned mixed reagent as the electroplating solution, the anode is graphite, and the cathode is treated red copper, at a pH of 6.5, a temperature of 55°C, and a current density of Electroplating for 2h under the condition of 3A/dm ² can prepare Cu-W-Co alloy coating on the cathode, as shown in Figures 3 and 4.

After testing, the composition of the coating is: Cu68.64%, Co18.92%, W12.44%, and the surface hardness is 213HV. At room temperature, the coating has no corrosion in 3.5% NaCl solution. The contact resistance of the coating is 24.7mΩ, and the oxidation rate at 600°C is 5.86×10 ^-4 g/cm ² . The coating is on the MMU-5G wear test machine, the load is 60N, the sliding speed is 50r/min, and the wear time is 0.5 hours, the wear rate is 0.248mg/h.

Example 3

The electroplating solution of the electrodeposited Cu-W-Co alloy coating, the electroplating solution includes the components of the following concentrations: soluble copper salt 35g/L, soluble cobalt salt 90g/L, sodium tungstate 70g/L, complexing agent 226g/L L, buffering agent 15g/L, brightener 1.0g/L, wetting agent 0.1g/L, additive 0.1g/L, wherein the molar fraction ratio of complexing agent to metal ion is 1.2:1, soluble copper salt is sulfuric acid Copper, soluble cobalt salt is cobalt sulfate, complexing agent is sodium citrate, buffering agent is boric acid, brightener is 1,4 butynediol, wetting agent is sodium lauryl sulfate, additive is cerium sulfate.

The method for electrodepositing a Cu-W-Co alloy coating, its specific steps are as follows: use the above-mentioned mixed reagent as the electroplating solution, the anode is graphite, and the cathode is treated red copper, at a pH of 6.5, a temperature of 55°C, and a current density of Electroplating for 2h under the condition of 3A/dm ² can prepare a Cu-W-Co alloy coating on the cathode, as shown in Figures 5 and 6.

After testing, the composition of the coating is: Cu63.48%, Co26.08%, W10.44%, and the surface hardness is 194HV. The coating has no corrosion in 3.5% NaCl solution at room temperature. The contact resistance of the coating is 26.5mΩ, and the oxidation rate at 600°C is 5.86×10 ^-4 g/cm ² . The coating is on the MMU-5G wear test machine, the load is 60N, the sliding speed is 50r/min, and the wear time is 0.5 hours, the wear rate is 0.250mg/h.

Example 4

The electroplating solution of the electrodeposited Cu-W-Co alloy coating, the electroplating solution comprises the components of the following concentrations: soluble copper salt 5g/L, soluble cobalt salt 60g/L, sodium tungstate 50g/L, complexing agent 100g/L L, buffering agent 5g/L, brightener 0.2g/L, wetting agent 0.1g/L, additive 0.1g/L, wherein the molar ratio of complexing agent to metal ion is 1:1, and the soluble copper salt is The mixture of copper sulfate and copper chloride with a molar ratio of copper ions of 1:1, the soluble cobalt salt is a mixture of cobalt sulfate and cobalt chloride with a molar ratio of cobalt ions of 1:1, and the complexing agent is coke with a mass ratio of 1:1:1 A mixture of sodium phosphate, pyrophosphoric acid and citric acid, the buffer is ammonium chloride, the brightener is a mixture of butynediol, polyethylene glycol, gelatin and saccharin with a mass ratio of 1:1:1:1, wetting agent It is sodium lauryl sulfate, and the additive is lanthanum chloride.

The method for electrodepositing a Cu-W-Co alloy coating, its specific steps are as follows: use the above mixed reagent as the electroplating solution, the anode is graphite, and the cathode is treated high-conductivity pure copper, at a pH of 4 and a temperature of 25°C 1. Electroplating for 0.5h under the condition of a current density of 1A/dm ² , the Cu-W-Co alloy coating can be prepared on the cathode.

Example 5

The electroplating solution of the electrodeposited Cu-W-Co alloy coating, the electroplating solution includes the components of the following concentrations: soluble copper salt 50g/L, soluble cobalt salt 120g/L, sodium tungstate 150g/L, complexing agent 300g/L L, buffering agent 40g/L, brightener 3g/L, wetting agent 1g/L, additive 1g/L, wherein the molar ratio of complexing agent to metal ion is 1.3:1, and the soluble copper salt is copper sulfate, The soluble cobalt salt is cobalt sulfate, the complexing agent is a mixture of potassium sodium tartrate, ethylenediamine and fluoboric acid with a mass ratio of 1:1:1, the buffer is sodium acetate, and the brightener is sodium saccharin with a mass ratio of 1:1:1 , a mixture of glucose and coumarin, the wetting agent is sodium dodecyl sulfate, and the additive is lanthanum sulfate.

The method for electrodepositing a Cu-W-Co alloy coating, its specific steps are as follows: use the above-mentioned mixed reagent as the electroplating solution, the anode is graphite, and the cathode is treated high-conductivity pure copper, at a pH of 11 and a temperature of 80°C 1. Electroplating for 3 hours under the condition of a current density of 20A/dm ² , the Cu-W-Co alloy coating can be prepared on the cathode.

Example 6

The electroplating solution of the electrodeposited Cu-W-Co alloy coating, the electroplating solution includes the components of the following concentrations: soluble copper salt 25g/L, soluble cobalt salt 80g/L, sodium tungstate 100g/L, complexing agent 150g/L L, buffering agent 25g/L, brightener 1.5g/L, wetting agent 0.5g/L, additive 0.8g/L, wherein the molar fraction ratio of complexing agent to metal ion is 1.2:1, soluble copper salt is sulfuric acid Copper, soluble cobalt salt is cobalt sulfate, complexing agent is boric acid, brightener is thiourea, wetting agent is sodium lauryl sulfate, additive is lanthanum chloride.

The method for electrodepositing a Cu-W-Co alloy coating, its specific steps are as follows: use the above-mentioned mixed reagent as the electroplating solution, the anode is graphite, and the cathode is treated high-conductivity pure copper, at a pH of 10 and a temperature of 60°C 1. Electroplating for 2.5 hours under the condition of current density of 18A/dm ² , the Cu-W-Co alloy coating can be prepared on the cathode.

Claims (9)

1. the electroplate liquid of a galvanic deposit Cu-W-Co alloy layer, it is characterized in that: this electroplate liquid comprises the component of following concentration: soluble copper salt 5 ~ 50g/L, solubility cobalt salt 60 ~ 120g/L, sodium wolframate 50 ~ 150g/L, complexing agent 100 ~ 300g/L, buffer reagent 5 ~ 40g/L, brightening agent 0.2 ~ 3g/L, wetting agent 0.1 ~ 1g/L, additive 0.1 ~ 1g/L, wherein complexing agent is 1 ~ 1.3:1 with the molar fraction ratio of metal ion.

2. the method for a galvanic deposit Cu-W-Co alloy layer, it is characterized in that concrete steps are as follows: to comprise the component of following concentration: soluble copper salt 5 ~ 50g/L, solubility cobalt salt 60 ~ 120g/L, sodium wolframate 50 ~ 150g/L, complexing agent 100 ~ 300g/L, buffer reagent 5 ~ 40g/L, brightening agent 0.2 ~ 3g/L, wetting agent 0.1 ~ 1g/L, the mix reagent of additive 0.1 ~ 1g/L is electroplate liquid, wherein complexing agent is 1 ~ 1.3:1 with the molar fraction ratio of metal ion, anode is graphite, high conductivity fine copper or the copper alloy matrix of negative electrode for processing, at PH, be 4 ~ 11, temperature is 25 ~ 80 ℃, current density is 1 ~ 20A/dm ²under condition, electroplate 0.5 ~ 3h, can on negative electrode, prepare Cu-W-Co alloy layer.

3. electroplate liquid or the method for galvanic deposit Cu-W-Co alloy layer according to claim 1 and 2, is characterized in that: described soluble copper salt is the arbitrary proportion mixture of copper sulfate or copper sulfate and cupric chloride.

4. electroplate liquid or the method for galvanic deposit Cu-W-Co alloy layer according to claim 1 and 2, is characterized in that: described solubility cobalt salt is the arbitrary proportion mixture of rose vitriol or rose vitriol and cobalt chloride.

5. electroplate liquid or the method for galvanic deposit Cu-W-Co alloy layer according to claim 1 and 2, is characterized in that: described complexing agent is the mixture of one or more arbitrary proportions of pyrophosphate salt, tetra-sodium, Citrate trianion, citric acid, Seignette salt, quadrol, fluoroboric acid, fluoroborate.

6. electroplate liquid or the method for galvanic deposit Cu-W-Co alloy layer according to claim 1 and 2, is characterized in that: described buffer reagent is boric acid, borate, ammonium salt or acetate.

7. electroplate liquid or the method for galvanic deposit Cu-W-Co alloy layer according to claim 1 and 2, is characterized in that: described brightening agent is one or more arbitrary proportion mixtures of butynediol, polyoxyethylene glycol, gelatin, asccharin, soluble saccharin, glucose, tonka bean camphor, thiocarbamide.

8. electroplate liquid or the method for galvanic deposit Cu-W-Co alloy layer according to claim 1 and 2, is characterized in that: described wetting agent is dodecyl sulfate or dodecane sulfonate.

9. electroplate liquid or the method for galvanic deposit Cu-W-Co alloy layer according to claim 1 and 2, is characterized in that: described additive is rare earth chloride or rare earth sulfuric acid thing.

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